I recently bought a Duratrax Axis with a .21 engine. It is broken in, has had about about 25-20 tanks through it.

The problem is when I try to take the car up to top speed at full throttle, the engine bogs down, and the car slows down. The car works normally when you give it full throttle, just not when trying to max out the engine at high speeds. Gudging by the sound, Im pretty sure its not hitting redline.

Could it be running too lean? I tried turning the high speed screw toward rich, and it still happens.

ok, thanks for the input. I think it is running too lean, because it started bogging down after i put better intake tubing on it. I suppose the more air flow made the carb run a little lean. I havent had a chance to take it out again, but ill try resetting the carb settings for a little richer.